Lathe-dog



(No Model.)

W. E. SIDNELL.

LATHE DOG.

Patented Aug. '7, 1888.

W'Z'Zhesses fm/enfor:

m z m .a h 2 m UNITE STATES PATENT OFFICE.

\VILLIAM E. SIDNELL, OF CUYAHOGA FALLS, OHIO.

LATH E-DOG.

SPECIFICATION formingpart of Letters Patent No. 282,577, dated August'7, 1883.

Applicalion filed February 2, 1883. (No model.)

To all whom, it may concern/.-

Be it known that I, XVILLIA E. SIDNELL, a citizen of the United States,residing at Guyahoga Falls, in the county of Summit and State of Ohio,have invented a new and useful Improvement in Lathe-Dogs, of which thefollowing is a specification.

My invention relates to 1athe-dogs adapted to grasp and hold in thelathe the ends of rods or shafts upon which screw-threads have been cutor formed.

The obj cct of my invention is to provide devices whereby suchscrewthreaded rods may be grasped and held without bruising, mar ring,or injuring the screw-thread. Hereto-' fore it has been customary toaccomplish this end by interposing between the rod and thegrasping-surfaces a plate or piece of copper or other soft metal. Thisis a clumsy contrivance and objectionable.

Myinvention consists in the mechanism illustrated in the accompanyingdrawings, wherein Figure 1 is a front elevation of my improvedlathe-dog, and Fig. 2 avertical central section of Fig. 1 at the line a:x.

The body A does not differ in its general form from those in common use,and it is provided with a set-screw, 0, located and operating in theusual manner. Within the body A is a chamber, in which fit two bits orjaws, B B, provided upon their contiguous faces with semicircularopenings, the two openings being provided with similar screw-threads, soarranged that when the jaws meet the thread is continuous. The lower jawmaybe integral with the body, the upper one alone having motion. Aswinging gate, D, holds the bits in place, and permits their removal andthe substitution of others.

In operation the screw-thread of the jaws should be the same asthethread on the rod to be clamped, whereby the latter can be firmly heldwithout injury. 7

To adapt the dog to rods having screwthreads of different pitch andsize, different dogs may be used or different bits for the same dog.

I claim as my invention- 1. A lathe-dog provided with jaws for grippingscrew-threaded rods, said jaws having upon their contiguous facesscrew-threaded semicircular openings, substantially as shown, and forthe purpose specified.

2. A lathe-dog for holding screw-threaded rods, provided with a chamberfor the reception of bits, in combination with pairs of bits adapted tofit in said opening, said bits being provided upon their contiguousfaces with semicircular. screw-threaded openings, substantially asshown, and for the purpose specified.

In testimony that I claim the foregoing I have hereunto set my hand this30th day of December, 1882.

XVILLIAM E. SIDNELL.

\Vitnesses:

CHAS. F. HARRISON, G. 1?. HUMPHREY.

